This invention relates generally to a system and method for introducing medical devices into vasculature. In particular, the present invention is concerned with the parallel introduction of a second guidewire into vasculature of the body, into which one guidewire has already been introduced, in such a way as to prevent entanglement of the guidewires. The present invention is also directed to facilitating removal of a dilator from vasculature without having to retract it the entire guidewire length. As used herein, the term xe2x80x9cproximalxe2x80x9d refers to a location on the device closest to the clinician using the device. Conversely, the term xe2x80x9cdistalxe2x80x9d refers to a location on the device farthest from the clinician and closest to the patient into whom the device is to be inserted.
For many medical purposes it is important to introduce devices, both permanently and for temporary diagnostic purposes, through the skin and underlying tissue layers into blood vessels or other locations inside the body of a patient. One of the earliest methods used to place such devices into the body involved cutting an opening in the body, inserting the device and then either closing the wound around the device or after the device has been removed. Because of the high skill and specialized medical facilities required to accomplish such a procedure, as well as the risk of trauma and infection, a need arose to develop less-invasive methods.
It is well established that percutaneous methods, involving creating a small opening in tissue and the use of devices such as dilators to gain access to vasculature, allow for the introduction of medical devices into the body without some of the risks associated with earlier methods. In particular, the size of the cut down employed to gain access to a vessel could be minimized. However, the use of a dilator alone requires that the medical device be inserted quickly once the dilator is removed. Additionally, such systems can also have associated therewith the risk of bleeding, damage to the medical device, or damage to the body during insertion.
It has also been established that the use of a thin-walled peel-away introducer sheath secured to a dilator at its proximal end provides for the introduction of medical devices while reducing some of the risks associated with dilator-only systems. The peel-away sheath allows removal of the dilator while leaving the sheath inside the body, thereby maintaining access to the expanded tissue opening and providing a conduit for the medical device. Additionally, such systems can reduce the tendency of the dilator to migrate proximally when it is initially introduced through the skin and subcutaneous tissue.
One drawback of conventional introducer devices becomes apparent when more than one guidewire is required for a particular procedure. When more than one guidewire is introduced into a single vessel, there is a possibility that they may become entangled. Another drawback of present devices is that removal of the dilator requires it to be retracted along the entire guidewire.
Accordingly, there is a need for a device and method that facilitates the insertion of more than one guidewire into vasculature while avoiding the potential for entanglement as well as permits a dilator to be removed without having to retract it along the entire guidewire length. The present invention fulfills these and other needs.
Briefly, and in general terms, the present invention is directed to a new and improved device and method for introducing medical devices within the vasculature of the body. The novel features of the present invention include a dual lumen introducer and inner member with longitudinally extending grooves. The dual lumen introducer allows a second wire (for example, a guidewire or a medical device manipulation wire) to be introduced into a single vessel without becoming entangled with a first guidewire already introduced. The introducer can be used with more than two wires and with other types of diagnostic or therapeutics devices, for example angiographic catheters. The use of an inner member or dilator with grooves formed along an outer surface thereof allows the same to be removed without having to retract it along the entire guidewire length. In other words, the guidewire slips easily out of the grooves.
In one aspect, the dual lumen introducer of the present invention embodies a hub, an inner member or dilator with longitudinally extending grooves, and a tear-away sheath. In use, the introducer device is threaded over a guidewire which has been inserted into the vasculature either percutaneously via a needle or other conventional surgical techniques. The introducer is then employed to introduce another wire(s) into the patient""s vasculature. Thereafter, the dilator is removed from the vasculature, leaving the sheath to maintain access to the vessel. Alternatively, the sheath can be peeled apart allowing the wires to be released from the dilator before the dilator is removed from the vasculature. The sheath can be removed as necessary by pulling the sheath proximally and simultaneously peeling it apart. Medical devices can then be introduced into the vasculature via the guidewires.
In another aspect of the invention, the hub includes two or more lumens; one for backloading the device over a guidewire already inserted into the vasculature and others for facilitating the introduction of another guidewire(s) into the vasculature. These lumens operate to separate the guidewires and prevent the guidewires from becoming crossed or entangled. It is contemplated that the dilator be bonded to the hub. The sheath, which is slid over the dilator, has a handle at its proximal end which locks to the hub. An internal bore of the sheath and the longitudinal extending grooves form lumens for receiving the guidewires.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.